This blog follows and explains the processes behind interesting geological events. The emphasis is on those events that are energetic, explosive, and have led to, or have the potential to lead to, disasters.

Welcome!

This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Wednesday, June 2, 2010

Gulf of Mexico Natural Oil Seep Rate vs. Deepwater Horizon Seep Rate

Photo from BP via Reuters, published in NYTimes.com on June 2, 2010

I will rarely post a fairly lengthy direct quote here, but this one is worth it and from an expert, Cutler Cleveland. He was a student of Bruce Hannon's here, and is a professor at BU. We used his sustainability text in our sustainability course.

First published in the Encyclopedia of Earth
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"Some reports in the media attempt to downplay the significance of the release of oil from the Deepwater Horizon accident by arguing that natural oil seeps release large volumes of oil to the ocean, so why worry? Lets look at the numbers.

Natural seeps can be thought of as natural springs from which liquid and gaseous hydrocarbons (hydrogen-carbon compounds) leak out of the ground. Oil seeps are fed by natural underground accumulations of oil and natural gas. Satellite images have identified hundreds of areas where oil is likely to seep from the Earth's crust into the waters of the Gulf of Mexico. These seeps occur over a wide range of the 615,000 mi² (1.6 million km²) Gulf. A 2003 study by the National Research Council and a 2009 report by oil spill expert Dagmar Schmidt Etkin indicate that between 560,000 and 1,400,000 barrels per year (1,534 to 3,835 barrels per day) seep into the Gulf of Mexico from natural sources. Dozens of natural seeps have been identified off the coasts of Louisiana and Texas, some in the region of the Deepwater Horizon site.

These natural seeps are quasi-continuous or chronic inputs that represent a "background" rate of oil input that have been in existence for hundreds or thousands of years. As the term "seep" implies, the rate of oil release from these sources is much smaller than human spills that often release large, concentrated pulses of oil. One of the largest and most intensively studied seepage areas lies off Coal Oil Point, in Santa Barbara County, California. Individual seeps in this area release an estimated 80 to 100 barrels (3,360 to 4,200 gallons) of oil per day; Deepwater Horizon is releasing 12,000 to 19,000 barrels per day.

The Deepwater Horizon site releases 3 to 12 times the oil per day compared to that released by natural seeps across the entire Gulf of Mexico. By May 30, the Deepwater Horizon site had released between 468,000 and 741,000 barrels of oil, compared to 60,000 to 150,000 barrels from natural seeps across the entire Gulf of Mexico over the same 39 day period.

Natural seeps are not constantly active; the volume of oil released can vary considerably throughout the day and from day to day. As a result, only a small area around the source is actually exposed to "fresh" non-degraded oil, which is its most toxic state.

Marine and coastal organisms and ecosystems presumably have adapted to the natural rate of oil input. Indeed, most organisms living in the regions near natural oil seeps have no special adaptations to the oil. Researchers at Woods Hole Oceanographic Institute and the University of California/Santa Barbara studied natural seeps off the coast of California. They found that as the oil moved upwards in the water column, a wide range of microbes consume the oil and produce intermediate products, and that those intermediate products are then converted by another group of microbes to natural gas and other compounds. Their research suggests that oil from natural seeps normally stays in the water for between ten hours to five days.

Oil that does make it to the surface from natural seeps can spread out very widely. One gallon of oil can spread out to cover more than a full square mile, forming an extremely thin film on the surface, about one-hundredth of a millimeter thick. Under these conditions, the oil is not hazardous. Some of the oil in that thin sheen evaporates within seconds or minutes after it reaches the surface.

A sudden, concentrated and massive pulse of oil from an event such as the Deepwater Horizon disaster presents a fundamentally more acute stress to marine and coastal systems. The amount, rate and spatial concentration of crude oil released from such an event overwhelm the natural mechanisms of oil dispersal and breakdown, producing the significant ecological effects that we observe."

National Research Council Committee on Oil in the Sea. 2003.Oil in the Sea III: Inputs, Fates, and Effects. National Research Council Ocean Studies Board and Marine Board Divisions of Earth and Life Studies and Transportation Research Board. National Academy Press, Washington, DC, USA. 265 pp.

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==>My book:The Dynamics of Disaster <==

Published by W.W. Norton--Click on image to go to Amazon.com

Synopsis of Book and Reviews

If you want to learn a bit of the science behind earthquakes, landslides, volcanic eruptions, tsunamis, rogue waves, cyclones and hurricanes, and tornadoes, this is an introduction that weaves together stories of various disasters--some barely known to much of the world--their causes and dynamics, and some suggested actions we can take to protect ourselves. The book is available both in paper and as an audio CD.

"This is a fantastic book. I've recommended to colleagues at FEMA and am using it as a text for my disaster classes. It really demonstrates how knowledge of the environment should inform policy. It was a page turner for me!"--Dr. Trish on Customer Reviews at Amazon.com

''Geologist Kieffer argues that we don't understand disasters as well as we should. She contrasts 'stealth disasters' caused by long-term human impact, including climate change and soil erosion, with natural disasters or 'acts of God,' which are also increasingly affected by human actions . . . [A] highly accessible look at disasters.'' --Booklist

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"If you are an amateur weather geek, disaster wonk or budding student of the earth sciences, you will want to read this book. (If you're squeamish, skip the chapter titled "A Plague of Snakes.")--Seattle Times by Mary Ann Gwinn

"[T]he clarity of Kieffer’s writing, coupled with her careful choice of supporting graphics, makes the content engaging and accessible to a wide readership." Alison Stokes in TheTimesHigherEducation

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"Both general readers and working scientists will enjoy this well-written book--and learn some things they did not know...Summing up: Highly recommended. Lower-division undergraduates through professionals; general audiences."--by Seth Stein in Choice Reviews Online (of the American Library Association), April 2014

"This [impressive] book ought to be placed in the hands of politicians, engineers, insurance assessors and, frankly, anyone who sees sense in understanding the processes and systems that guide our planet." --Geographical, December 2013, by Jonathan Wright

This book is part of a recent trend--one that is just beginning, but is likely to grow--in which scientists, especially young ones, seek to move beyond the "disasters are bad" view presented in beginner classes to a more sophisticated and nuanced view…Seth Stein in Physics World (U.K.)

"It is like a "Magic School Bus" outing for adults, with Kieffer acting as Ms. Frizzle, guiding the reader around the world to disaster hotspots, where she analyzes and breaks down the physical characteristics that contribute to events in those areas."--Summit Daily, December 20, 2013

#1 in list of Best Sellers: Geology, from May 2013 to March 2014. LibraryJournal.com

Victoria Raschke's Reviews (Jan. 09, 2019) Kieffer's explanations of the how natural disasters occur is perfectly suited to the interested layperson. The section on rogue waves was worth the price of admission in that it explains something that always seemed kind of supernatural. If you have any interest at all in understanding our living planet and why it sometimes feels like it would be happy to be rid of us, this is the book for you.